The continuing objective of this project is the evaluation and implementation of new methodology whenever if offers the advantages of more rapid or precise identification of microorganisms recovered from patient samples or when it results in cost reduction. The cause for weakly positive coagulase tests for Staphylococci that could not be phage typed was determined to be acidity due to incubation in a CO2 incubator. A new schema for the identification of "non-fermenting gram negative bacilli" has been developed, tested, and adopted for use. The API enteric strip is under evaluation for identification of the Enterobacteriaceae. During serotyping of the Serrati marcescens, it was discovered that the apparent fluctuations in flagellar antigens were due to phase variation. Crytococcal antigens and Toxoplasma antibodies are determined on a routine basis and photomicrographs are made for documentary files. A new system for rapid retrieval of stored stock cultures was devised. A review of blood culture media from which Candida spp. and Torulopsis glabrata were most frequently recovered has led to utlization of several Sabouraud's slants for blood of patients suspect of having fungemia.